This invention relates to a disc player with a centering mechanism which, in inserting a disc into the disc inserting opening thereof, operates to position the disc at the s center of the disc inserting opening. In particular, it relates to a disc-double insertion preventing mechanism.
Recently, a compact disc has been developed which has a recording layer having pits corresponding to digital signals obtained by converting analog sounds (hereinafter referred merely as "a disc", when applicable). With the disc, analog sounds are optically reproduced by using a laser beam applied by the reading head of a CD (compact disc) player. The disc is much superior both in tone quality and in operability to conventional LP record discs. Hence, the compact disc together with its CD player has quickly come into wide use. Accordingly, CD players to be mounted on vehicles have been developed (hereinafter referred to as "vehicle disc players", when applicable). One example of the vehicle disc players is as shown in FIG. 1. In FIG. 1, reference numeral 101 designates a disc 12 cm in diameter in which pieces of music have been recorded. When the disc 101 is inserted into a disc inserting opening 102, it is conveyed to a predetermined position (which is substantially the center of the CD player) by a loading mechanism 103, where it is fixedly mounted on the turntable 105 by a clamper arm 104. The disc 101 thus mounted is rotated by a spindle motor (not shown), so that the pieces of music are reproduced with a reading head (not shown).
On the other hand, a disc 106 of 8 cm in diameter, which is much smaller in diameter than the disc 101 of 12 cm in diameter, has been proposed in the art.
The above-described conventional vehicle CD player suffers from the following difficulties: It is rather difficult to insert a disc into the wide disc inserting opening 102 at the middle, since the opening 102 is formed for the large diameter disc, and therefore it is necessary to use the centering mechanism. Particularly when the player is mounted on a travelling vehicle, it is further difficult to insert the 8 cm disc into the disc inserting opening 102 at the middle, because of the vibration of the vehicle.
This difficulty may be eliminated by provision of the centering mechanism which moves the disc 106 to the middle of the disc inserting opening 102 if it is shifted therefrom. Such a mechanism may be provided in the vicinity of the disc inserting opening 102.
On the other hand, in the vicinity of the disk inserting opening 102, there is a disc double loading preventing member 108 for preventing a new disc from being inserted into the player when the player already receives the other disk. The double loading preventing member 108 is driven to pivot in the directions of arrow W by an opening/closing mechanism 107 provided on a side opposite to the loading mechanism 103. With such a mechanism, during the playback of the CD player, the double loading preventing member 108 is driven by the opening/closing mechanism 107 to thereby close the disk inserting opening 102 to prevent another disc from being inserted erroneously.
However, such a conventional system suffers from a disadvantage such that the overall mechanism of the CD player would be complicated due to the provision of the centering mechanism, the other independent double loading preventing member 108 and the opening/closing mechanism 107. This would increase a manufacture cost. Also, it is difficult to enhance a mechanical reliability of the operation.